Postmarc View Options

The button with the capital R is the
"reset view" button. The first click on the reset button will
"un-zoom" the model, returning its magnification factor to unity.
The second click will return the model to the default location,
namely a top view with the nose to the viewer's left.
The button with the eye is the "viewpoint" control. This is used
to quickly set the view direction. The popup screen requests three
values. These are NOT angles, but rather X Y Z coordinates of the
point in space at which the viewer's eye is located. Perspective
has not been implemented, and so distance from the origin is not
important. For example eye location (1 0 0) will be looking forward
(toward the origin) along the X axis. Location (-1 0 0) looks aft
along the X axis toward the origin. Positive Z values indicate an
eye position above the plane of the model. Positive Y values
indicate a position to the model's right or starboard side.
Coordinates may be fractional. Their absolute size is not important;
rather, their relative sizes determine the angle from which the
model is viewed. Thus, (10 5 4) produces the same view as
(1.0 0.5 0.4).

To get rear, starboard side, or top views, enter hit the X, Y, or
Z key. For front, port, or bottom views hit <Shift-X>, <Shift-Y>,
or <Shift-Z>.

The "twist" or rotate button is next. Enter a rotation angle in degrees and
the view will be rotated about the screen normal. Positive rotation
is clockwise.

The next button controls magnification (the icon resembles a
magnifying glass). Normally the default magnification (1.0) scales
the model to fill the screen. A magnification factor larger than
1.0 zooms close to the model and a number smaller than 1.0 zooms
away from the model. Negative numbers are meaningless and not
accepted.

The zoom button is next. This icon is a large Z with a partial box
surrounding it. Once a model is on the screen, the user can click
and release on this button, then move the mouse to one corner of the
desired viewing area, click the left button, and, with the left mouse
button depressed, drag a box around part of the model where a closer
look is desired.

To unzoom, click on the "reset" (R) button.

The framing or "move" button is the last button in the view group.
Click and release this button, then move the cursor to some location
on the screen. Hold the left mouse button and drag a line. When the
mouse button is released the model will translate in the same
direction and for the same distance as the mouse did.